A V I C U L A. 



Plate XVI. 



Species 61. (Mus. Cuming.) 



AvicuLA INQUINATA. Avic. tcstd angude obligm, con- 

 vexiuscula, leevigatd, viride castaneo-rufo iuquinaid, 

 epidermide liratd minute serratd versus marginem m- 

 dtdd, aid late superjicialiter canaliculatd. 



The dyed Avicula. Shell narrowly oblique, rather 

 convex, smooth, stained with bright chestnut-red, 

 covered towards the margin with a minutely-serrated 

 ridged epidermis, wing broadly superficially chan- 

 nelled. 



Hob. Singapore. 



Very obliquely formed, with the wing unusually broadly 



superficially channelled. 



Species 62. (Mus. Cuming.) 

 AviCDLA EXIMIA. Avic. testd angmte elongatd, tenui, 

 castaneo-rufd, iridescente, epidermide minute serratd 

 versus marginem indutd, valvd dextrd eleganter marmo- 

 ratd et radiatd. 

 The delicate Avicula. Shell narrowly elongated, 

 thin, iridescent, chestnut-red, covered towards the 

 margin with a minutely-seixated epidermis, right 

 valve elegantly mottled and rayed. 



Hab. ? 



An extremely delicate elongately-winged shell, of a pe- 

 culiar iridescent chestnut-colour. 



Species 63. (Mus. Cuming.) 

 Avicula gregata. Avic. testd oblique rotmtdatd, cou- 

 ve-xd, aid longissimd, gracili; pellncido-purpureo-rufd; 

 epidermide fibrosa foliatd minute serratd indutd. 

 The gregarious Avicula. Shell obliquely rounded, 

 convex, with a wing very long and slender ; transpa- 

 rent purple-red; covered with a minutely-serrated 

 festooned fibrous epidermis. 

 Hab. Tutudla, Samoa Islands. 



A transparent purple-red shell, rather rounded and con- 

 vex, with a slender elongated wing, covered with a beauti- 

 fully-serrated, festooned, fibrous epidermis. 



Species 64. (Mus. Cuming.) 

 Avicula semi-saggita. Avic. testd oblique subquadratd, 



convexiiisculd, cinereo-grised vel nigricante, purpurea 

 undatd, epidermide fibrosa minute foliatd indutd in 

 liris confertis concentricis. 

 The half-arrow Avicula. Shell obliquely subquad- 

 rate, rather convex; ash-grey or blackish, purple 

 waved, covered with a minutely-festooned fibrous 

 e))idermis in close-set concentric ridges. 

 Lamarck, Anira. sans vert. vol. vii. p. 98. 



Eab. ? 



This is the nearest to agree with Lamarck's definition 

 of .-/. semi-sagitta. The identification is necessarily doubt- 

 ful. 



65. (Mus. Cuming.) 



Avicula argentea. Avic. testd suborbiculari, aid lata 

 productd, solidinsculd, argenteo-grised, purpureo un- 

 datd, pallide radiatd, epidermide via: nulla. 



The silvery avicula. Shell suborbicular, with a broad 

 produced wing, rather solid, silvery-grey, rippled 

 with purple, faintly rayed, epidermis very slight. 



Hab. ? 



Of a peculiar silvery hue, prettily rayed, witli rippled 



purple, having white rays passing through it. 



This shell has all the appearance of a distinct species, 

 but it is entirely covered with a coating of coral. 



Species 67. (Mus. Cuming.) 

 Avicula heteroptera. Avic. testd oblique orbiculari, 



aid longissimd, convexd, lavigatd, margaritaced, vivide 



rufo-caslaned, obscure anguste radiatd, valvis irujequa- 



libus. 

 The dissimilarly-winged Avicula. Shell obliquely 



orbicular, with a very long wing, convex, smooth, 



pearly, blight reddish-chestnut, obscurely narrowly 



rayed, valves unequal. 

 Lamarck, Anim. sans vert. vol. vii. p. 98. 



Avicula sterna, Gould. 

 Hab. New Holland. 



There can be little doubt of this being the true La- 

 marckian A. heteroptera. 



